Company Decision

This is a first in human, phase 1, multicenter, open-label study to determine the safety and tolerability of IGM-2644 as a single agent in participants with relapsed and/or refractory MM, for whom standard therapy does not exist, has proven to be ineffective or intolerable, or is considered inappropriate. Dose escalation and dose expansion cohorts will be enrolled to evaluate safety, preliminary efficacy, and further define a RP2D. The total length of the study, from screening of the first participant to the end of the study, is expected to be approximately 60 months.

Patients will be enrolled in two stages: a dose-escalation stage and a dose expansion stage. The escalation stage will investigate single agent IGM-2644 safety and tolerability in patients with relapsed and/or refractory multiple myeloma. The dose expansion cohort(s) will further evaluate safety, PK/PD, and preliminary efficacy of the recommended phase 2 dose (RP2D).

IGM-2644 will be administered intravenously (IV).

Inclusion Criteria:

• Adults > 18 years at time of consent
• ECOG performance status of 0 or 1
• Relapsed and/or refractory multiple myeloma after ≥ 3 prior lines; Must have failed treatment with an IMiD, PI, and anti-CD38 therapy
• Measurable disease per the IMWG response criteria
• Adequate marrow and organ function without transfusion or growth factor support within 7 days prior to screening
• Willing and able to undergo bone marrow aspirate and biopsy per protocol

Exclusion Criteria:

• Inability to comply with study and follow-up procedures
• History of clinically significant primary amyloidosis, plasma cell leukemia, Waldenstrom macroglobulinemia or myelodysplastic syndrome
• Received chemotherapy, biologics, or small molecule therapy within 21 days or 5 half-lives, whichever is shorter
• Use of any non-approved or investigational agent ≤ 4 weeks prior to the first dose of study drug.
• Received last prior anti-CD38 monoclonal antibody treatment within 28 days before first planned dose of the study drug
• Current Grade > 1 toxicity, with the exception of Grade 2 peripheral neuropathy, alopecia, or toxicities from prior anti-tumor therapy that are considered irreversible
• Large-field radiotherapy within 28 days prior to Day 1 (radiation to a single site as concurrent therapy is allowed)
• Prior autologous stem cell transplant within 180 days prior to Day 1
• Prior allogeneic stem cell transplant